Add generate-borgmatic-config end-to-end test.

tests/end-to-end/test_generate_config.py

@@ -0,0 +1,16 @@
+import os
+import subprocess
+import tempfile
+
+
+def test_generate_borgmatic_config_with_merging_succeeds():
+    with tempfile.TemporaryDirectory() as temporary_directory:
+        config_path = os.path.join(temporary_directory, 'test.yaml')
+        new_config_path = os.path.join(temporary_directory, 'new.yaml')
+
+        subprocess.check_call(f'generate-borgmatic-config --destination {config_path}'.split(' '))
+        subprocess.check_call(
+            f'generate-borgmatic-config --source {config_path} --destination {new_config_path}'.split(
+                ' '
+            )
+        )